Age-related olfactory loss is an important public health problem affecting approximately 14 million older Americans. The profound burden this sensory impairment causes in the daily lives of older people is associated with a substantially decreased quality of life, affecting critical functions such as safety, nutrition, sensation of pleasure, and general well-being. Because olfaction declines over time, the clinical impact will increase as our population ages. Previous studies of this decline in olfactory physiology in humans have been limited, requiring novel approaches to understanding factors that affect this process. In this application, I propose to characterize factors that underlie susceptibility to ag-related olfactory decline. Using data from the Memory and Aging Project (MAP) and the National Social Life, Health, and Aging Project (NSHAP), I plan to identify biodemographic factors that are associated with age-related olfactory decline. These robust resources, in which health and olfactory data have been collected previously along with relevant biomeasures, will allow an analysis of medical and psychosocial parameters that are associated with olfactory loss in older persons. In parallel, I will examine genetic risk factors for this phenotype by performing genome-wide association studies (GWAS) using existing genotype data in MAP and in the Hutterites, a population which has a number of distinct advantages for genetic mapping, including uniform environmental exposures and rich clinical information on relevant co-morbidities. This line of study will involve analysis of several olfactory traits for identifying gene(s) involved in the decline of the sense of smell. Lastly, using available, high quality DNA specimens, I will replicate these genetic associations in NSHAP. A structured training program will include courses in genetic epidemiology and demography for the development of analytic expertise, culminating in a Master's degree. Mentorship will be multidisciplinary by three renowned scientists who possess significant experience in genetics, demography, and aging. This award will allow me to develop the skills necessary to direct an independent research program on the impact of olfactory decline and other nasal diseases on older persons. This approach, utilizing three unparalleled and complementary data sets, will provide insight into the pathophysiology of age-related olfactory decline which, ultimately, can lead to improved prognostic, diagnostic and therapeutic modalities. Completion of these studies will serve as a model for understanding the non- genetic and genetic influences on sensory decline in aging.